You feel tired or sleepy during the day even after an apparent full night’s sleep.

You are overweight.

Your neck size is larger than 17".

You feel depressed.

Are you nodding off at inappropriate times? Do you always feel tired? Are you a loud and frequent snorer? If so, you may be one of the millions of Americans who suffer from a sleep disorder. And besides affecting the quality of your sleep, some of these disorders may affect your heart health.

Nearly 70 million Americans of all ages and backgrounds are believed to suffer from sleep disorders such as sleep apnea, narcolepsy and insomnia, prompting some to call it an epidemic. In fact, sleep experts say millions of Americans suffer sufficiently to warrant medical attention. Yet only a small percentage of these are aware of the nature of their condition and that effective treatment is available.

What is a sleep disorder?

A sleep disorder interferes with your normal pattern of sleep and may cause fatigue, anxiety, depression, inability to concentrate and memory loss. Common disorders are:

Obstructive sleep apnea. This disorder is characterized by loud snoring and gasping or choking for breath during sleep due to an obstructed airway. This results in nightly sleep disruption. If untreated, the disorder may result in extreme fatigue and daytime sleepiness. Obstructive sleep apnea may also contribute to high blood pressure and increase the risk of heart attack and stroke.

Insomnia. Insomnia is characterized by the persistent inability to fall asleep or stay asleep. Over time, the lack of sound sleep may lead to excessive daytime sleepiness and fatigue. Loss of memory, reduced ability to concentrate, memory loss and more frequent illness may follow.

Narcolepsy. A sufferer of narcolepsy frequently will experience an irresistible urge to sleep. Other symptoms include temporary weakness when excited or surprised, inability to move or talk upon falling asleep or awakening and experiencing vivid dreamlike scenes when waking up or falling asleep.

Restless legs syndrome (RLS). RLS is characterized by crawling or tingling sensations in the legs while awake and an irresistible urge to move the legs during rest. Leg movement may cause frequent awakenings and result in excessive daytime sleepiness, an inability to carry out normal duties and feelings of anxiety and depression.

If you suspect that you have any of these sleep disorders, you should consult your physician immediately. All of them are serious, and some may be life threatening.

Sleep apnea and your heart

Though the connection is not fully understood, a person with sleep apnea is twice as likely to suffer from high blood pressure and three times as likely to suffer from heart disease than someone in the general population.

Researchers at the University of Wisconsin confirmed the connection between sleep apnea and high blood pressure. They monitored the blood pressure of 147 volunteers for 24 hours a day. The bad news: The more serious the sleep apnea, the greater the frequency of high blood pressure. The good news: When sufferers of sleep apnea receive proper treatment, they usually are able to sleep more soundly and their blood pressure goes down.

Help is now available

The great majority of people with sleep disorders don’t realize they have a problem. Consequently, their disorders go untreated. However, help is available. Physicians trained in sleep medicine can evaluate you and, if necessary, recommend treatments to help you sleep better. Such treatments may include behavioral changes (weight loss, smoking cessation, change in sleeping position and better sleep habits), breathing devices (nasal continuous positive airway pressure and dental appliances) and surgery (removal of the adenoids and tonsils and removal of excess throat tissue).

If you’re not getting a good night’s rest, the steps you take to improve your sleep may also protect your heart and help you enjoy a happier, more productive life.